A teaser for the A-list actor's new movie, War Machine, was released on Wednesday, March. 1 — and while the upcoming film looks like a must-see, we can't get over how unrecognizable Brad looks with gray hair!

In the flick, the 53-year-old actor portrays a member of the US Army, Gen. Stanley A. McChrystal. The Netflix movie — set to release on May 26 — is a satire of America's war in Afghanistan.

Christian Bale

Christian is a pro at altering his appearance for roles! He lost a shocking 62 pounds to play a man whose insomnia leads him to becoming emaciated in The Machinist. After that film wrapped, he had only had six weeks to bulk up to play Batman in 2005's Batman Begins.

Tilda Swinton

The actress — or should we say human chameleon? — looked seriously unrecognizable in Trainwreck! For her role as a no-holds-barred magazine editor, the Oscar winner ditched her signature pompadour pixie haircut and instead donned a long, wavy wig and heavy makeup. And frankly, we're still barely convinced it really is Tilda in the movie!

Renee Zellweger

The actress packed on a reported 20 pounds each time she played the title character in the Bridget Jones franchise! To put weight on her naturally slim figure, Renee abandoned her normally strict workout regimen and swapped salads for 4,000+ calorie meals instead.

Hilary Swank

To play an aspiring boxer in Million Dollar Baby, Hilary dedicated more than four hours per day, six days per week to weight training and consumed nearly 210 grams of protein per day. All of her hard work paid off when the actress won the Academy Award for Best Actress in 2004!

Chris Hemsworth

The actor underwent a drastic weight loss to portray Owen Chase, the first mate of the vessel Essex, which is later destroyed by a whale, leaving the ship's crew stranded at sea for 90 days in In the Heart of the Sea.